package com.kungfu.utils;

import java.io.UnsupportedEncodingException;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

/**
 * 3DES加密
 *
 * @author SHANHY(365384722@QQ.COM)
 * @date 2015-8-18
 */
public class ThreeDES {

    private static final String Algorithm = "DESede"; // 定义 加密算法,可用  
    // DES,DESede,Blowfish

    /**
     * 加密方法
     *
     * @param keybyte 加密密钥，长度为24字节
     * @param src     被加密的数据缓冲区（源）
     * @return
     * @author SHANHY
     * @date 2015-8-18
     */
    public static byte[] encryptMode(byte[] keybyte, byte[] src) {
        try {
            // 生成密钥  
            SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);

            // 加密  
            Cipher c1 = Cipher.getInstance(Algorithm);
            c1.init(Cipher.ENCRYPT_MODE, deskey);
            return c1.doFinal(src);
        } catch (java.security.NoSuchAlgorithmException e1) {
            e1.printStackTrace();
        } catch (javax.crypto.NoSuchPaddingException e2) {
            e2.printStackTrace();
        } catch (java.lang.Exception e3) {
            e3.printStackTrace();
        }
        return null;
    }

    /**
     * 解密
     *
     * @param keybyte 加密密钥，长度为24字节
     * @param src     加密后的缓冲区
     * @return
     * @author SHANHY
     * @date 2015-8-18
     */
    public static byte[] decryptMode(byte[] keybyte, byte[] src) {
        try {
            // 生成密钥  
            SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);

            // 解密  
            Cipher c1 = Cipher.getInstance(Algorithm);
            c1.init(Cipher.DECRYPT_MODE, deskey);
            return c1.doFinal(src);
        } catch (java.security.NoSuchAlgorithmException e1) {
            e1.printStackTrace();
        } catch (javax.crypto.NoSuchPaddingException e2) {
            e2.printStackTrace();
        } catch (java.lang.Exception e3) {
            e3.printStackTrace();
        }
        return null;
    }

    /**
     * 转换成十六进制字符串
     *
     * @param b
     * @return
     * @author SHANHY
     * @date 2015-8-18
     */
    public static String byte2hex(byte[] b) {
        String hs = "";
        String stmp = "";

        for (int n = 0; n < b.length; n++) {
            stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
            if (stmp.length() == 1)
                hs = hs + "0" + stmp;
            else
                hs = hs + stmp;
            if (n < b.length - 1)
                hs = hs + ":";
        }
        return hs.toUpperCase();
    }

    /**
     * 测试
     *
     * @param args
     * @author SHANHY
     * @date 2015-8-18
     */
    public static void main(String[] args) throws UnsupportedEncodingException {
        // 添加新安全算法,如果用JCE就要把它添加进去  
        Security.addProvider(new com.sun.crypto.provider.SunJCE());

        // 24字节的密钥（我们可以取apk签名的指纹的前12个byte和后12个byte拼接在一起为我们的密钥）  
        final byte[] keyBytes = SecretUtils.build3DesKey(MD5Utils.getMD5("xiehe123456"));
        String szSrc = "1515141264198";
        String key = new String(keyBytes);
        System.out.println(key);
        System.out.println("加密前的字符串:" + szSrc);

        byte[] encoded = encryptMode(keyBytes, szSrc.getBytes());
        String result = bytesToHexString(encoded);
        System.out.println("加密后的字符串:" + result);

        byte[] srcBytes = decryptMode(keyBytes, hexStringToBytes(result));
        System.out.println("解密后的字符串:" + (new String(srcBytes)));
    }

    public static String bytesToHexString(byte[] src) {
        StringBuilder stringBuilder = new StringBuilder("");
        if (src == null || src.length <= 0) {
            return null;
        }
        for (int i = 0; i < src.length; i++) {
            int v = src[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }

    /**
     * Convert hex string to byte[]
     *
     * @param hexString the hex string
     * @return byte[]
     */
    public static byte[] hexStringToBytes(String hexString) {
        if (hexString == null || hexString.equals("")) {
            return null;
        }
        hexString = hexString.toUpperCase();
        int length = hexString.length() / 2;
        char[] hexChars = hexString.toCharArray();
        byte[] d = new byte[length];
        for (int i = 0; i < length; i++) {
            int pos = i * 2;
            d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
        }
        return d;
    }

    private static byte charToByte(char c) {
        return (byte) "0123456789ABCDEF".indexOf(c);
    }
}  
